Sigma factor genes sigC, sigE, and sigG are upregulated in heterocysts of the cyanobacterium Anabaena sp. strain PCC 7120.
نویسندگان
چکیده
We used gfp transcriptional fusions to investigate the regulation of eight sigma factor genes during heterocyst development in the cyanobacterium Anabaena sp. strain PCC 7120. Reporter strains containing gfp fusions with the upstream regions of sigB2, sigD, sigI, and sigJ did not show developmental regulation. Time-lapse microscopy of sigC, sigE, and sigG reporter strains showed increased green fluorescent protein fluorescence in differentiating cells at 4 h, 16 h, and 9 h, respectively, after nitrogen step down.
منابع مشابه
Regulation of Genes Involved in Heterocyst Differentiation in the Cyanobacterium Anabaena sp. Strain PCC 7120 by a Group 2 Sigma Factor SigC
The filamentous cyanobacterium Anabaena sp. strain PCC 7120 differentiates specialized cells for nitrogen fixation called heterocysts upon limitation of combined nitrogen in the medium. During heterocyst differentiation, expression of approximately 500 genes is upregulated with spatiotemporal regulation. In the present study, we investigated the functions of sigma factors of RNA polymerase in t...
متن کاملGroup 3 sigma factor gene, sigJ, a key regulator of desiccation tolerance, regulates the synthesis of extracellular polysaccharide in cyanobacterium Anabaena sp. strain PCC 7120
The changes in the expression of sigma factor genes during dehydration in terrestrial Nostoc HK-01 and aquatic Anabaena PCC 7120 were determined. The expression of the sigJ gene in terrestrial Nostoc HK-01, which is homologous to sigJ (alr0277) in aquatic Anabaena PCC 7120, was significantly induced in the mid-stage of dehydration. We constructed a higher-expressing transformant of the sigJ gen...
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Superoxide dismutases (Sods) play very important roles in preventing oxidative damages in aerobic organisms. The nitrogen-fixing heterocystous cyanobacterium Anabaena sp. strain PCC 7120 has two Sod-encoding genes: a sodB, encoding a soluble iron-containing Sod (FeSod), and a sodA, encoding a manganese-containing Sod (MnSod). The FeSod was purified and characterized. A recombinant FeSod was als...
متن کاملPosttranscriptional regulation of glutamine synthetase in the filamentous Cyanobacterium Anabaena sp. PCC 7120: differential expression between vegetative cells and heterocysts.
Genes homologous to those implicated in glutamine synthetase (GS) regulation by protein-protein interaction in the cyanobacterium Synechocystis sp. strain PCC 6803 are conserved in several cyanobacterial sequenced genomes. We investigated this GS regulatory mechanism in Anabaena sp. strain PCC 7120. In this strain the system operates with only one GS inactivation factor (inactivation factor 7A ...
متن کاملAn increase in the level of 2-oxoglutarate promotes heterocyst development in the cyanobacterium Anabaena sp. strain PCC 7120.
In the filamentous cyanobacterium Anabaena sp. strain PCC 7120, a starvation of combined nitrogen induces differentiation of heterocysts, cells specialized in nitrogen fixation. How do filaments perceive the limitation of the source of combined nitrogen, and what determines the proportion of heterocysts? In cyanobacteria, 2-oxoglutarate provides a carbon skeleton for the incorporation of inorga...
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ورودعنوان ژورنال:
- Journal of bacteriology
دوره 189 22 شماره
صفحات -
تاریخ انتشار 2007